Page 84 - Modular design for machine tools

Basic Knowledge: What Is the Modular Design? 51

from the variation of the tool slide, this case can be interpreted as being
midway between the traditional (manual operation) and the NC
machines, and from such a point of view the machine is worth record-
ing in the developing history.
At this immature era, the NC machine tool was manufactured by
simply attaching the NC controller to the machine tool and modifying
the structure in part to equip, e.g., the ball screw and servomotor. In
due course, the machine tool maintains the traditional appearance. In
other words, the structural appearances were in mixed condition, i.e.,
that with built-in type NC or stand-alone NC, which simply attached
the NC controller to the traditional machine. With the advance of the
related technologies, the smart NC machine tool came to fruition, where
the synergy of the NC technology and the structural design was skill-
fully used, and on this extension, the MC and TC have, at last, became
a reality in the mid-1970s. To understand such a trend, Fig. 1-36 shows
a developing history of TC originating with the engine lathe and its vari-
ants.
In short, the MC itself can manage various machining methods so far
executed by the drilling, milling, and boring machines, whereas the TC
includes, in principle, an advanced function of milling, although even
the NC turning machine can manage milling in part by the special
attachment fixed to its turret.
It is worth pointing out that even in the beginning of the 1970s, simul-
taneous quinary-axis control was already established, and obviously
we conclude that the NC machine tool has enough flexibility beyond our
expectation across the whole machining methods usually employed
together with rendering the modular design useless. In fact, the machin-
ing function of TC is, in general, a synergy of turning, drilling, boring,
and milling. Thus the machine is, in certain cases, equipped with a
turret column having plural turret heads or tool magazines (see Fig. 2-17),
resulting in the very flexible tooling layout, although turning is domi-
nant. Consequently, between the middle and late 1970s, modular design
was not often employed, because the TC and MC prevailed, and there
was no necessity to provide the machine tool with the flexibility based
on the modular design. In fact, the modular principle was applied to the
design of the attachment in the case of TC, e.g., those for offset of rotat-
ing tool and twin-drilling, but not to the design of the structural con-
figuration. Importantly, the flexibility of the NC machine tool was
further reinforced by the skillful fusion of the NC software and tooling
layout in the beginning of the 1980s, and the designer became progres-
sively less interested in the modular design thereafter. With further
due development of the TC and MC, the structural body configuration
was scarcely designed by the modular principle, and such a trend was
accelerated. Table 1-4 shows some examples of the NC turning machine